Control system for a drilling apparatus

ABSTRACT

A roll control and deflection device for a drilling apparatus which may include a hydraulic drive mechanism, an instrumentation unit, a drill motor, and a drill bit. The deflection unit is mounted between the drill motor and the drill bit and includes a foot which is extendible against the drill hole wall, forcing the drill to deflect from the previous drilling axis. A roll control apparatus is coupled between the drive mechanism and the mounting for the deflection unit and will roll the deflection unit to any angular position about the axis of the drill unit.

United States Patent 1 Bourne, Jr. et a1.

[ CONTROL SYSTEM FOR A DRILLING APPARATUS [75] Inventors: Henry A. Bourne, Jr., Ponca City,

Okla; Rondon L. Schroeder, Shinnston, W. Va.

[73] Assignee: Continental Oil Company, Ponca City, Okla.

[22] Filed: Nov. 26, 1973 [21] Appl. No.: 419,157

1 1 June 10, 1975 3,554,301 1/1971 Adkins et a1 175/24 3,554,302 l/197l Adkins et a1...... 175/73 X 3,589,454 6/1971 Coyne i 4 175/61 X 3,598,445 8/1971 Winberg........... 175/61 X 3,630,295 12/1971 Coyne et a1 175/61 X 3,797,589 3/1974 Kellner et al. 175/94 Primary Examiner-David H. Brown Attorney, Agent, or Firm william J. Miller [57] ABSTRACT A roll control and deflection device for a drilling apparatus which may include a hydraulic drive mechanism, an instrumentation unit, a drill motor, and a drill bit. The deflection unit is mounted between the drill motor and the drill bit and includes a foot which is extendible against the drill hole wall, forcing the drill to deflect from the previous drilling axis. A roll control apparatus is coupled between the drive mechanism and the mounting for the deflection unit and will roll the deflection unit to any angular position about the axis of the drill unit.

15 Claims, 22 Drawing Figures PATENIEDJUHIO I975 8,888,319

SHEET 3 a5 89 9 ma we /24 a CONTROL SYSTEM FOR A DRILLING APPARATUS BRIEF DESCRIPTION OF THE PRIOR ART Horizontal drilling may require three essential features: first, a drill; second, a means of forcing the drill into the ground; and third, a means of controlling the drill during its operation underground. The guidance systems used for controlling the underground operation of a drill generally comprise two type. The first type comprises surface-generated signals and means for conveying the signals to the horizontal drill. Such means can be, for example, an antenna. The horizontal drill includes means for receiving the signal and following some predetermined path in accordance with the signals.

Patents to James C. Coyne, U.S. Pat. Nos. 3,589,454 and 3,712,391 describe a horizontal drill having such a control system. Means can also be provided in the drill for controlling its operation. Such means can be, for example, a radiation detector or radiation transmitter and detector. The drill can be controlled internally in accordance with the radiation detected, or information can be transmitted out of the hole being drilled and controlling information redirected to the drill from outside the hole.

Such an apparatus is described in US. patent application Ser. No. 246,297 now US. Pat. No. 3,823,787 filed Apr. 2l, 1972, by I-Iaworth et al and assigned to the same assignee as this invention.

The above-related patents also describe means for deflecting the drill, the deflection means comprising a pivotal joint which is mechanically deflected. The position of the hinged joint is varied by a rotary actuator which is not described in detail in the patents.

BRIEF DESCRIPTION OF THE INVENTION This invention describes a specific roll control mechanism or rotary actuator in combination with a unique deflection device. The roll control mechanism comprises a unit which is actuated by pistons which operate on a ratchet assembly. The ratchet assembly provides a means of transmitting the movement of the roll control mechanism to the outside body of the drill. The deflection unit is mounted near the drill bit and comprises a single shoe which is forced against the drill hole wall in any position necessary to provide force against the drill, thereby controlling its direction. The same by draulic system provides both operation of the roll control mechanism and the deflection unit.

The invention further features a deflection unit that can be operated either in conjunction with the roll control mechanism above described or as an individual unit in a system that does not contain a roll control mechanism but where control of the drill is desired.

The invention further features means for launching the horizontal drill horizontally into the stratum to be bored.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a side view of a horizontal drill incorporating the hydraulic pressure mechanism, the instrument package including the roll control mechanism, the drill motor and associated gear reduction box, the deflection unit, and the drill bit;

FIG. 2 is a cross-sectional view of the roll control mechanism;

FIG. 3 is an expanded view of the piston block and the spring block used in the roll control mechanism;

FIG. 4 is a cross-sectional view of FIG. 2 taken through lines 44;

FIG. 5 is a cross-sectional view of FIG. 2 taken through lines 44 and used to illustrate the operation of the roll control mechanism;

FIG. 6 is a cross-sectional view of FIG. 2 taken through lines 66;

FIG. 7 is a cross-sectional view of FIG. 2 taken through lines 7-7;

FIG. 8 is a cross-sectional view of the slipring assembly for the electrical circuitry and the rotary assembly of the hydraulic circuitry for the roll control mechamsm;

FIGS. 9A, 9B, and 9C show the cam arrangement for inserting the electrical plugs for mating electrical plugs in a blind assembly used in the device illustrated in FIG.

FIG. 10 is a side cross-sectional view of the deflection control mechanism;

FIG. 11 is a partial crosssectional top view of the deflection control mechanism shown in FIG. 10;

FIG. 12 is a cross-sectional view of FIG. 10 taken through lines I2I2;

FIG. 13 is another embodiment of the roll and deflection control mechanism;

FIG. 14 illustrates the operation of the embodiment shown in FIG. 13;

FIG. 15 is an embodiment illustrating the deflection control mechanism used for drilling horizontal holes without the use of a roll control mechanism;

FIG. 16 is a hydraulic drive unit and external roll control mechanism useful in the device illustrated in FIG. 15;

FIG. 17 is an end view of the apparatus illustrated in FIG. 16;

FIG. 18 is a launch control device useful in launching the apparatus illustrated in FIG. 1;

FIG. 19 is an enlarged side view taken through lines l919 of FIG. 18', and

FIG. 20 is a cross-sectional view taken through lines 2020 of FIG. 18.

GENERAL DESCRIPTION Referring to FIG. I a horizontal drill is illustrated and essentially comprises a hydraulic pressure mechanism generally referred to by the number 10. Mechanism 10 provides force for a drill l1. Mechanism 10 comprises a hydraulic cylinder 12 which has a plurality of pressure feet 13 attached on the outside thereof. Pressure feet 13 are adapted to be hydraulically forced against the drill hole wall when the unit is applying pressure to drill 11 and released during the retraction stage. Unit 14 provides a mounting for a second set of pressure feet 15 which are selectively engaged against a drill hole wall by hydraulic pressure during the retraction stage. A shaft 16 extends through hydraulic cylinder 12 and into instrument package 17. A hydraulic piston (not shown) is mounted inside cylinder 12 and rigidly attached to shaft 16. An electrical drill motor 18 (which may also be hydraulic) is attached to instrument package 17 and has a deflection mounting end 19 attached to a deflection unit 20. A drill shaft 21 is rigidly attached to drill 11 by any suitable means, such as tapered threads. Hydraulic pipes, generally referred to by the number 21, provide control to the hydraulic pressure mechanism 10, to the roll control unit (not shown), and to deflection control unit 20. Electrical wires 22 provide power for the instrument package 17 and drill motor 18. Pipe 23 provides drilling fluid for drill 11.

OPERATION The device disclosed in FIG. 1 essentially functions as follows: Hydraulic pressure of the pipes 21 expands pressure feet 13 against the drill hole wall. Additional hydraulic pressure is applied inside cylinder 12 against the hydraulic piston. Hydraulic pressure then applies force against shaft 16 which will force the drill in the direction of arrow 24. When the hydraulic piston has traveled as far as it can inside cylinder 12, pressure feet are expanded against the drill hole wall, pressure feet 13 are retracted, hydraulic fluid is applied to the opposite side of the piston. and the cylinder 12 will move back toward drill 11. The reverse procedure is then followed, and the unit will again drive the drill in the direction of arrow 24. If roll control is needed, hydraulic pressure (from 350 to 1,500 pounds depending on the amount of friction encountered) can be applied through one of the pipes 21 which is connected to the roll control mechanism. The mechanism will be actuated causing instrument package 17, motor 18, deflection unit 20, and drill 21 to be rotated a predetermined number of degrees. If deflection of the drill is necessary. hydraulic fluid pressure to the roll control mechanism is sustained until an orifice permits sufficient fluid to cause an increase in deflection unit 20, resulting in deflection unit moving against the wall of the bore hole, thereby deflecting the drill II.

ROLL CONTROL MECHANISM A more detailed explanation of the roll control mechanism is illustrated by reference to FIGS. 2 through 7.

The roll control mechanism provides an essential means for deflecting the drill in any predetermined direction. The roll control mechanism will also counter any tendency to roll caused by the hydraulic pressure mechanism 10. The deflection device will then permit controlled deflection of the longitudinal axis of drill bit 1] and its associated equipment in a longhole drill train so that the hole axis remains either horizontal or deflected by an amount necessary to maintain the horizontal drill in some predetermined prescribed path.

Referring to FIG. 2 but with particular reference to FIG. 3, a mandrel 31 is attached to shaft 16 through an end portion 32 by means of threads 33. A piston block 34 is attached to mandrel 31 by means of cap screws 35. A spring block, generally referred to by number 36, is slidably positioned over mandrel 31. The entire block assembly comprising piston block 34 and spring block 36 is retained on mandrel 31 by means of a nut 37 secured to mandrel 31 by threads 38.

The open end of piston block assembly 34 is machined so that there are two opposed quadrants 40 and 41 remaining, each having an included angle of 90. The open end of spring block assembly 36 is machined so that there are two opposed quadrants 42 and 43 remaining, each having an included angle of 83. Thus, when spring block assembly 36 is rotatably engaged with piston block assembly 34 on mandrel 31, there is 7 of rotational freedom between blocks 36 and 34. Piston block assembly 34 is bored and counterbored in six locations to accommodate six pistons 47. The spring block assembly 36 is bored in six locatons to receive six springs 48 which, when assembled, are preloaded in compression and secured with spring keepers 49 which are in turn held in position by a keepe:v rad 50. Keeper rod 50 is inserted through holes 51 in spring block 36 and holes 52 in keepers 49. Each of the cpers also includes a threaded portion 53 used to compress the springs during the assembly procedure, thereby permitting the insertion of the keeper rods 50 into holes 52 (see FIGS. 4 and 5). On the end of spring block assembly 36, opposite the quadrants 42 and 43, are mounted nine pawl pins 61 which are press-fitted into holes 40 apart which are drilled into the end of spring block assembly 36 (see FIGS. 6 and 7). Nine ratchet pawls 62 are rotatably mounted on pawl pins 61 and are urged inwardly against a drive ratchet 63 by an elastic member 64 which encircles pawls 62 and applies biasing pressure toward drive ratchet 63 by exerting pressure against a pin 65 rigidly secured normal to the surface of pawls 62. Pins 65 are press-fitted into holes drilled into ratchet pawls 62. Drive ratchet 63 is rotatably mounted over mandrel 31 and is rotatably locked to a bearing housing 66 by a plurality of drive ratchet pins 67 which are press-fitted into holes drilled into bearing housing 66. Bearing housing 66 is secured axially and rotatably with respect to instrument package 17 by four countersunk cap screws 68. An antitorque ratchet 76 fits over mandrel 31 and is keyed to mandrel 31 by key 77. A plurality of pawls 78 is rotatably secured to a plurality of pawl pins 79. Pawl pins 79 are press-fitted into bearing housing cap 80. Bearing housing cap 80 is secured to hearing housing 66 by means of a plurality of screws 81. Each pawl 78 carries a pin 65. An elastic member 82 encircles the pawls and engages pins 65 in a manner to bias the pawls into the antitorque ratchet 76.

A thrust bearing race 83 and a radial bearing race 84 provide free movement for rotation and thrust of the housing with respect to the mandrel 31. The entire roll control mechanism is secured to the mandrel by means of an end plate 84 and tubular housing 85. A radial bearing 86 provides freedom of movement of the man drel with respect to the outer housing. Seals 87 throughout the unit prevent entrance of drilling fluids into the roll control mechanism. Screws 88 secure the housing to end plate 84. The entire unit is enclosed in a second tubular housing 89. Fluid movement into and out of the unit is provided by several passages and channels. Basically the fluid movement comprises a hydraulic input to control the roll control mechanism and the deflection control unit 20 and a drilling fluid passage for supplying liquid to the drill bit so that the chips will be washed away from the bit and out of the hole as drilling progresses. The hydraulic input comprises a pipe 90 which has an opening 91 into a circumferential groove 92 in mandrel 31. Groove 92 has a passage 93 into passage 94, through passages 95 and 96 to passage 97, which connects to passage 98 into piston 47 and passage 99 into pipe 100 which eventually is connected to the deflection control unit. Drilling fluid enters pipe out holes 106, into passage 107 through holes 108, and into the space 109 between housing 89 and housing 85.

The electrical connections to the instrument package 17 and to drill motor 18 are made through pipe 110 to the inside 11] of mandrel 31 which is formed of a pipe 1 12.

OPERATION OF ROLL CONTROL MECHANISM When it is desired to rotate the instrument package 17, which by construction includes drill motor 18, deflection unit and drill 11, hydraulic pressure is applied to pipe 90 which is transferred through hole 91, circumferential groove 92, passages 93, 94, 95, 96, 97, and 98 to the back of pistons 47. The system is designed so that. at approximately 350 pounds per square inch, the precompression on springs 48 will be overcome and block quadrants 42 and 43, which are connected to spring block 36, will begin to rotate (see FIG. 5). Full hydraulic pressure of 500 pounds per square inch will cause full rotation of 7 of spring block assembly 36 with respect to piston block assembly 34. The system is designed to operate up to 1,500 pounds per square inch to provide sufficient torque to overcome friction when the drilling unit is in the hole. The 7 rotation of spring block assembly 36 is transmitted through pawl pins 61 to ratchet pawls 62. Three of the nine ratchet pawls 62 (see FIG. 6), which are spaced 120 apart, will be engaged with drive ratchet 63 causing it to turn counterclockwise through an angle of 7. The 7 rotation of drive ratchet 63 is transmitted to hearing housing 66 through drive ratchet pins 67 and to instrument package 17 through bolts 68. The 7 rotation is also transmitted through bolts 81 to bearing housing cap 80 to pawl pins 79 to pawls 78 (see FIG. 7). At the end of the 7 rotational stroke, two of the pawl pins 79 (shown in FIG. 7), which are spaced 180 apart, will become engaged with antitorque ratchet 76 which is rotatably locked to mandrel 31 by key 77. when hydraulic pressure in pipe 90 and subsequently to passage 98 is lowered, from 500 pounds per square inch to about 375 pounds per square inch, the relationship of the internal parts will return to that shown in FIG. 5. With continued reduction in pressure, springs 48 will cause spring block assembly 36 to rotate 7 clockwise to the position shown in FIG. 4, with driving pistons 47 having returned to their initial position. Ratchet pawls 62 will move in a clockwise direction with respect to drive ratchet 63. At this time a different set (3) of ratchet pawls 62 will engage with the teeth of drive ratchet 63.

It should be noted that drive ratchet 63 and antitorque ratchet 76 each have 30 teeth which are on a 12 spacing. Drive ratchet pawls 62 are located with 40 angular spacing. Consequently, during each cycle of operation, only three drive ratchet pawls 62, which are spaced 120 apart, are engaged with drive ratchet 63. Thus, for each continued rotation, a new set of pawls 62 is engaged. Similarly, as shown in FIG. 7, there are three pairs of ratchet pawls 78, each pair being 180 apart. Each pair is angularly spaced from adjacent pairs by 30; therefore, each pair is engaged during every third cycle. Although each cycle of operation produces 7 of relative rotation between piston block assembly 34 and spring block assembly 36, only 4 of the 7 is caught" and held prior to the initiation of the next cycle. Thus, for each cycle of operation, instrument package 17 is rotated 4 with respect to mandrel 31. The use of six power pistons was required to obtain the desired torque capability in the roll device to overcome frictional drag of the instrument package 17, drill motor 18, deflection unit 20 and drill 11. The net torque output at 1,500 pounds per square inch hydraulic pressure (after subtracting torque required to further compress springs 48 I is about 300 foot pounds.

SLIP-RING ASSEMBLY The instrument package requires both a source of power to operate and a return connection for transmitting multiplex information from the instrument package to the operator controlling the drill unit. Since the mandrel supplying the electric power through pipe and into pipe 100 (see FIG. 2). is stationary and since instrument package 17 is capable of rotation, because of the previously described roll control mechanism, some form of slip-ring assembly must be utilized to transmit hydraulic fluid through the unit to the deflection unit 20, electrical power to, and return signals from the instrument package. The apparatus for accomplishing the above is illustrated in FIGS. 8, 9A, 9B, and 9C. One of the problems in assembly of the roll control mechanism and the slipring unit is the inacces sibility of the slip-ring unit. Thus the unit shown in FIG. 8 is assembled essentially blind." Iipc 100 fits into mounting block through an opening 116 centrally located in block 115. Pipe 100 has a pointed end 117 to assist in making the blind insertion into opening 116. Hydraulic fluid from the inside of pipe 100 passes out of a hole 118 through the tube wall and into a circumferential groove 119. A passage I20 leads to a hydraulic coupling 121 and to a pipe 122 which eventually connects with deflection unit 20. Electrical connection is made to a slip-ring unit 123 through a female plug 124 and male plug 125. Wires 126 from male plug are connected to a plurality of slip-rings 127. Brushes 128 in contact with slip-rings 127 have a plurality of wires 129 coupled to the instrument package. In order to mate plug 124 with plug 125 in a blind situation. a camming arrangement is provided and is illustrated in FIGS. 9A, 9B. and 9C.

Referring to these figures, a first cam 128, which carries female plug 124, is attached to an extension 129 of pipe 112 and is rigidly secured thereto. Female plug 125 is attached to cam 130 which in turn is attached to tubular mounting 131 which carries slip-rings 127. Screws 132 are attached between tubular mounting 131 and plug 125. Both cams 128 and 130 are guided axially by pipe 100 illustrated in dotted lines in FIGS. 9A, 9B, and 9C. Each cam 128 and 130 carries a cam ing surface 133 and 134, respectively. Thus, as surface 133 strikes surface 134, earn 130 will rotate in either direction as illustrated by arrow 135 until the final position shown in FIG. 9C is accomplished. at which time the plugs will be properly mated.

DEFLECTION CONTROL UNIT The deflection control unit is illustrated in detail in FIGS. 10, 11 and 12. In the drawing illustrated the de flection unit is located between the drill motor 18 and the drill bit 11 and provides a mechanical means for causing the drill bit to drill ahead. upwardly, downwardly, or in any other predetermined direction. The deflection unit essentially comprises a main body which is bolted to the bearing housing 141 by means of a plurality of bolts 142. Drill motor 18 has a threaded shaft 143 connected to a shaft extension 144 connected to a second shaft extension 145 which is coupled through threads (not shown) to drill 11. Outside tubular housing 89 is sealed from bearing housing 141 by a plurality of O-ring seals 87. Bearings 148 provide rotational support between shaft extension 144 and bearing housing 141. The upper part of the main body 140 is machined with a cylindrical section 149 which is bored to provide a cavity for a spring 150. The lower part of main body 140 is machined with a cylindrical section 151 which is coaxial with the cylindrical section 149. A piston 152 fits over cylindrical section 141 and is sealed by an O-ring seal 153. A piston 1S4 fits over cylindrical section 149 and is sealed by an O-ring seal 155. Pistons 152 and 154 function as pressure shoes for the deflection unit. Side plates 156 (see FIG. 12) couple piston 154 to piston 152 and are secured by means of a plurality of screws 157. Hydraulic fluid is supplied to piston 151 from pipe 122 through coupling 1S8, passage 159, coupling 160, pipe 16], coupling 162, and passage 163. The distance measured from the top of piston 154 to the bottom of piston 152 is slightly less than the diameter of the hole formed by drill bit 11.

OPERATION OF DEFLECTION UNIT By proper regulation of the hydraulic pressure applied to the cavity between cylindrical section 151 and piston 152, pressure can be applied between piston 151 and the bore hole wall to control the direction of the drill axis. Because of gravity a drilling unit will normally tend to drill downwardly. Hydraulic fluid applied to piston 152 by a proper amount will maintain the drill properly oriented along a straight axis. If it is desired to drill downwardly, the hydraulic pressure level is lowered. The force exerted by spring 150 plus the force exerted by gravity produced by the cantilevered loads of the instrument package 17, motor 18, and the drill bit 11 will cause the bit to drill downwardly. Conversely, an increase in controlled hyraulic pressure will cause piston 152 to thrust against the bottom of the bore hole and urge the axis of the drill bit shaft 145 upwardly against spring 150, causing the drill bit 11 to drill upwardly. In the event it is desired to change the compass or azimuth heading of the drilled hole, the entire drilling assembly can be rolled by use of the roll device described previously so that the bottom piston 152 is positioned against any predetermined portion of the drill hole wall.

It has been found desirable for ease of operation in the simultaneous use of both the roll control mechanism and the deflection unit to provide an orifice and check valve 113 in pipe 122. The orifice will provide a means for the oil to reach piston 152 but at a rate which will normally take longer than four seconds. It has been found that approximately four seconds will provide ample time to operate the roll control mechanism. Thus, pressuring the roll control mechanism to at least 500 pounds, barring an excess amount of friction, will operate same. The oil pressure will also be transferred through pipe 122 to piston 152. Usually enough pressure will be provided to piston 152 to just center the deflection control unit during the operation of the roll control mechanism. When the oil pressure is re leased, the check valve 113 will immediately release the pressure in the series of pipes and passages between check valve 113 and piston 152.

ALTERNATE PLACEMENT FOR DEFLECTION FIGS. 13 and 14 illustrate an alternate placement for deflection unit 20. Referring to FIG. 13, hydraulic mechanism is connected to a roll control and deflection control unit 136 which contains deflection unit 20. Unit 136 is connected to drill motor 18 through a flexible joint 137. Drill motor 18 is connected directly to drill 11. A stabilizer 138 is mounted on drill motor 18 near the drill end of motor 18 and provides a rotational pivot for the deflection action.

The operation is described by referring to FIG. 14. When deflection unit 20 moves in the direction of arrow 139, pivot section 137 will force the drill downward in the direction of arrow 146 about stabilizer 138 which will force the drill in an upward direction as indicated by arrow 147. Since the deflection unit can be moved by the roll control mechanism in any direction, the drilling axis can be changed in any desired direction.

FIG. 15 shows a further alternate embodiment where the roll and power control unit. generally referred to by number 164, is outside the hole being drilled. The instrument package 17, drill motor 18, deflection unit 20, and drill 11 are as described in FIG. 1. Instrument package 17, however, is connected to power and roll control unit 164 by a plurality of hollow drill rods 165 which are supported in the hole, if desired, by stabilizers 166. Hydraulic control pipes 21 are coupled to a hydraulic control unit 167 and to the deflection unit 20. An electrical control system 168 is connected through electrical wires 22 to the instrument package 17 and to supply power to drill motor 18. Drilling fluid is supplied through pipe 23 down the center of drill rod 165 through drill motor 18 to drill 11.

An apparatus useful in providing the power and roll control 164 for the apparatus disclosed in FIG. 15 is illustrated in FIGS. 16 and 17 and essentially comprises a hydraulic cylinder 170 having a piston rod 171 coupled to drill rods 165. A roll control mechanism comprises a motor 172 mounted to a pair of bars 173 through a sliding bearing 174. Bars 173 are attached to a suitable frame 175. Motor 172 is coupled through gears 176 and 177 to piston rod 171. Piston rod 171 has an internal passage 178 coupled to the hollow drill rod 165 and to a rotatable coupling 179 which in turn is connected to drilling fluid pipe 23. Hydraulic pipes 180 and 18] are connected to a hydraulic control unit 167. A collapsible sleeve 182 may be mounted over bars 173 to protect them from dirt and other foreign objects. A hydraulically controlled vise 183 has a cylinder 184 with hydraulic lines 185 coupled to hydraulic control unit 167. A piston 186 is attached to piston rod 171 and suitably sealed.

Operation of the above device is as follows:

Hydraulic pressure applied to pipe 180 applies pressure between the end wall and piston 186, driving piston rod 171 forward. Roll control unit 164, being attached to piston rod 171 and slidable on bars 173, will move with the forward advance of piston rod 171. The advance of piston rod 171 will be transmitted to drill rods 165 and subsequently to drill 11. When the piston rod has advanced to the point where a joint 187 has nearly reached vise 183, the proper switch is activated and hydraulic pressure through pipes 185 will cause cylinder 184 to close the jaws of vise 183. Roll control motor 172, through gears 176 and 177, will rotate piston rod 171 to break joint 187. The piston rod 171 is then retracted by applying hydraulic pressure through pipe 181. A new drill rod is inserted and the roll control motor reversed in direction which will tighten the drill rod, whereupon vise 183 is then released.

During the preceding operation, the vise has prevented the drill from becoming disorientated. The

proper switch will then put the drill motor back into the roll mode if, for example, additional gears are needed (not shown).

LAUNCH TUBE Difficulties encountered with a horizontal drill are drilling the first 24 feet of hole, because of lack of support for the drilling assembly and lack of a drill hole wall for the hydraulic mechanism to operate against. In order to overcome these difficulties, a launch tube was invented and is illustrated in FIGS. 18, 19, and 20. The launch tube consists of sections of semicircular tubular elements bolted together and supported on three height-adjustable support stands. Provision is made for lateral movement of the launch tube with respect to the support standsv Further provision is made to anchor the launch tube against axial thrust.

Referring to the figures but in particular to FIG. 18, a launch tube assembly comprises two halfsections 201 made from 6-inch inside diameter aluminum pipe. Half-flanges 202 are welded to the ends of halfsections 201 and are bolted together with bolts 203 to form a continuous half-tube. A T-section 205 is welded to the bottom of each half-section 201 to provide stiffness to the overall unit. Shorter 6-inch inside diameter aluminum pipe half-sections 206 (four in number) are attached to the bottom sections 201 by hinges 207. A bolt 208 forms a pivot for hinges 207. The adjustable support stands are attached to bands 210 mounted in three locations along the launch tube assembly. A cylindrical section 211 is attached normal to each of the bands on the underside and fits into a mating vertically tubular section 212 which is welded to a sideplate 213 for a support assembly 214. A pair of rollers 204 is journaled in support assembly 214. A parallel rod or support bar 215 is welded to a vertical tubular support 216 which fits over a vertical tubular member 217. A support stand 218 supports vertical tubular member 217. Each vertical tubular member is provided with a plurality of holes 219 which permits positioning of horizontal support bars 215 at various elevations. Pins 220 support short tubular members 216 at the desired elevation. Conical half-sections 221 are welded to the ends of half-sections 201 and 206 to provide smooth entry for hydraulic hoses and electric cables. The entire assembly is anchored by means of cables 225 which are attached by any suitable means to half-sections 201 and to an anchor 226 which may be drilled and anchored to a rock face, for example.

Operation of the launch tube is as follows:

Each of the hinged half-sections 206 is opened to permit exposure to the bottom half-tubular section 201. The horizontal drill shown in FIG. 1 is then laid onto the cradle formed by half-section 201. Each of the top half-tubular sections 206 is then closed and pinned to form a continuous tube. When the horizontal drill is actuated, the hydraulic mechanism will have the side walls of the tube for applying driving force through pressure feet 13. Furthermore, the particular location to be drilled can be properly oriented by loosening pins 220 and adjusting the height of support bars 215 and reinserting pins 220. Rollers 204 will accommodate any horizontal adjustments necessary to properly align the tube with the area to be drilled. Anchors 226 and ca bles 225 will restrain the assembly from axial movement created when the drill enters the face being drilled.

CONCLUSIONS A roll control mechanism and deflection unit have been described for a horizontal drill. It is obvious that changes may be made in the particular manner of accomplishing the details of building the roll control mechanism and still be well within the scope of the invention as described.

A unique interconnection between the roll control mechanism and the deflection unit has also been described which provides for operation of the roll control mechanism essentially independent of the deflection unit and operation of the deflection device independently of the roll device.

It has also been illustrated that the roll control mechanism may be outside the hole and the deflection unit inside the hole and either located by the drill or at another location along the drill train.

The preferred embodiment has been described as a horizontal drilling apparatus. It is obvious that any use may be made of the roll control or deflection device.

' for example, in a vertical drilling operation, and still be within the spirit and scope of this invention. Further, other fluids, such as air, can be used in place of hyraulic fluid.

Changes may be made in the deflection control unit or its combination with the roll control mechanism and the location in which either is mounted with respect to the horizontal drill and still be well within the scope of the invention as described in the specification and appended claims.

We claim:

1. A roll control and deflection device for a drilling apparatus having a hydraulic drive mechanism, an instrumentation unit, a drill motor and a drill bit connected axially to form said drilling apparatus, comprising:

a. a deflection unit;

b. means for mounting said deflection unit between said drill motor and said drill bit, said deflection unit including a foot, means for extending said foot normal to the axis of said drilling apparatus, and

c. roll control means coupled between said hydraulic drive mechanism and said means for mounting said deflection unit, to roll said deflection unit to any angular position about the axis of said drilling unit.

2. An apparatus as described in claim 1 wherein said deflection unit includes a hydraulic cylinder and piston mounted between said drilling mechanism and said foot, spring biasing means mounted to bias said piston into said hydraulic cylinder and means to controllably apply hydraulic fluid into said hydraulic cylinder.

3. An apparatus as described in claim 1 wherein a first hydraulic line is connected to said roll control means and a second hydraulic line is connected from said first hydraulic line to said deflection unit.

4. An apparatus as described in claim 3 wherein a check valve means and orifice means are parallelly connected and in series with said second line and wherein said check valve means operates to release pressure buildup in said deflection unit upon reduction of pressure in said first hydraulic line and wherein said orifice means is timed to permit full operation of said roll control means without substantial pressure buildup in said deflection unit.

5. In a drilling apparatus having at least a drilling motor having a rotational axis and a drill bit connected through a shaft to said drilling motor a deflection unit comprising a:

a. mounting means attached between said drilling motor and said drill bit;

b. pressure application means slidably attached to said mounting means normal to the rotational axis of said drill motor; and means for axially positioning said pressure application means by axially rotating said mounting meansv 6. A deflection unit as described in claim wherein said mounting means is rigidly attached to said drilling motor.

7. A deflection unit as described in claim 6 wherein said means for positioning said pressure application means comprises a cylinder mounted on said mounting means and having its axis normal to the axis of rotation of said drilling motor, piston means sealably mounted inside said cylinder in contactual relation with said pressure application means, hydraulic inlet means connected to said cylinder for using said piston out of said cylinder and spring biasing means for returning said piston into said cylinder along with said pressure application means into said cylinder.

8. A deflection unit as described in claim 6 wherein said pressure application means comprises first and second feet mounted on diametrically opposite sides of said mounting means, side plates attached to opposite sides of said feet, slidably mounted to said mounting means, piston means positioned between said mounting means and one of said feet and spring biasing means positioned between said mounting means and said remaining foot.

9. A roll control device for a drilling apparatus having a pressure mechanism and a drill means comprising a fractional-rotation torque motor attached to said pressure mechanism and having its output connected through a drive means and an antitorque means to said drill means, and means for applying power to said torque motor to fractionally rotate said drill means a predetermined number of degrees.

10. A torque motor as described in claim 9 comprisi. a piston block and a spring block each comprising cylindrical tubular portions formed of oppositely facing quadrants, each of said quadrants forming said spring block forming an angle from the axis of said cylindrical tubular portion of at least 83;

b. means for mounting the quadrants of said piston and spring blocks to form a subtantially contiguous tubular surface;

0. piston means mounted in at least one of said quadrants of said piston block, said piston means in contactual relation with one of said quadrants of said spring block;

d. spring means retained in at least one of said quadrants of said spring block and in contactual relation with one of said quadrants of said piston block;

e. means for supplying power to said piston means;

f. means for mounting one of said blocks to said pressure mechanism; and

g. means for coupling said remaining block to said drive means and antitorque means.

11. A device as described in claim 9 wherein said drive and antitorque means comprises a drive ratchet rigidly coupled with respect to said drill means and a plurality of cooperating pawls coupled to said torque motor, an antitorque ratchet, means for rigidly mounting said antitorque ratchet to said pressure mechanism and means for rigidly mounting a plurality of antitorque pawls to said drill means.

12. Drill control apparatus comprising directional drilling apparatus for a drill adapted to form a borehole, said drill having a drill motor coupled substantially adjacent a drill bit comprising:

a. roll control apparatus coupled to said drill motor,

and

b. pressure deflection means mounted between said roll control apparatus and said drill bit to apply force against the wall of said borehole, thereby deflecting the axis of said drilling apparatus.

13. An apparatus as described in claim 12 wherein said pressure deflection means includes a hydraulic cylinder and piston mounted between said roll control apparatus and said drill motor and a yieldable coupling between said pressure deflection means and said drill motor.

14. An apparatus as described in claim 13 additionally including stabilizing means between said yieldable coupling and said drill bit.

15. An apparatus as described in claim 14 wherein said stabilizing means is located on said drill motor. 

1. A roll control and deflection device for a drilling apparatus having a hydraulic drive mechanism, an instrumentation unit, a drill motor and a drill bit connected axially to form said drilling apparatus, comprising: a. a deflection unit; b. means for mounting said deflection unit between said drill motor and said drill bit, said deflection unit including a foot, means for extending said foot normal to the axis of said drilling apparatus, and c. roll control means coupled between said hydraulic drive mechanism and said means for mounting said deflection unit, to roll said deflection unit to any angular position about the axis of said drilling unit.
 2. An apparatus as described in claim 1 wherein said deflection unit includes a hydraulic cylinder and piston mounted between said drilling mechanism and said foot, spring biasing means mounted to bias said piston into said hydraulic cylinder and means to controllably apply hydraulic fluid into said hydraulic cylinder.
 3. An apparatus as described in claim 1 wherein a first hydraulic line is connected to said roll control means and a second hydraulic line is connected from said first hydraulic line to said deflection unit.
 4. An apparatus as described in claim 3 wherein a check valve means and orifice means are parallelly connected and in series with said second line and wherein said check valve means operates to release pressure buildup in said deflection unit upon reduction of pressure in said first hydraulic line and wherein said orifice means is timed to permit full operation of said roll control means without substantial pressure buildup in said deflection unit.
 5. In a drilling apparatus having at least a drilling motor having a rotational axis and a drill bit connected through a shaft to said drilling motor a deflection unit comprising a: a. mounting means attached between said drilling motor and said drill bit; b. pressure application means slidably attached to said mounting means normal to the rotational axis of said drill motor; and means for axially positioning said pressure application means by axially rotating said mounting means.
 6. A deflection unit as described in claim 5 wherein said mounting means is rigidLy attached to said drilling motor.
 7. A deflection unit as described in claim 6 wherein said means for positioning said pressure application means comprises a cylinder mounted on said mounting means and having its axis normal to the axis of rotation of said drilling motor, piston means sealably mounted inside said cylinder in contactual relation with said pressure application means, hydraulic inlet means connected to said cylinder for using said piston out of said cylinder and spring biasing means for returning said piston into said cylinder along with said pressure application means into said cylinder.
 8. A deflection unit as described in claim 6 wherein said pressure application means comprises first and second feet mounted on diametrically opposite sides of said mounting means, side plates attached to opposite sides of said feet, slidably mounted to said mounting means, piston means positioned between said mounting means and one of said feet and spring biasing means positioned between said mounting means and said remaining foot.
 9. A roll control device for a drilling apparatus having a pressure mechanism and a drill means comprising a fractionalrotation torque motor attached to said pressure mechanism and having its output connected through a drive means and an antitorque means to said drill means, and means for applying power to said torque motor to fractionally rotate said drill means a predetermined number of degrees.
 10. A torque motor as described in claim 9 comprising: a. a piston block and a spring block each comprising cylindrical tubular portions formed of oppositely facing quadrants, each of said quadrants forming said spring block forming an angle from the axis of said cylindrical tubular portion of at least 83*; b. means for mounting the quadrants of said piston and spring blocks to form a subtantially contiguous tubular surface; c. piston means mounted in at least one of said quadrants of said piston block, said piston means in contactual relation with one of said quadrants of said spring block; d. spring means retained in at least one of said quadrants of said spring block and in contactual relation with one of said quadrants of said piston block; e. means for supplying power to said piston means; f. means for mounting one of said blocks to said pressure mechanism; and g. means for coupling said remaining block to said drive means and antitorque means.
 11. A device as described in claim 9 wherein said drive and antitorque means comprises a drive ratchet rigidly coupled with respect to said drill means and a plurality of cooperating pawls coupled to said torque motor, an antitorque ratchet, means for rigidly mounting said antitorque ratchet to said pressure mechanism and means for rigidly mounting a plurality of antitorque pawls to said drill means.
 12. Drill control apparatus comprising directional drilling apparatus for a drill adapted to form a borehole, said drill having a drill motor coupled substantially adjacent a drill bit comprising: a. roll control apparatus coupled to said drill motor, and b. pressure deflection means mounted between said roll control apparatus and said drill bit to apply force against the wall of said borehole, thereby deflecting the axis of said drilling apparatus.
 13. An apparatus as described in claim 12 wherein said pressure deflection means includes a hydraulic cylinder and piston mounted between said roll control apparatus and said drill motor and a yieldable coupling between said pressure deflection means and said drill motor.
 14. An apparatus as described in claim 13 additionally including stabilizing means between said yieldable coupling and said drill bit.
 15. An apparatus as described in claim 14 wherein said stabilizing means is located on said drill motor. 